I definitely would like to see the Deflector Burst effect in the game. The exact mechanics are negotionable and subject to game balance concerns. Simple approach might be to make it similar to Beam Overload, except that it might temporarily drop shields and reduce shield power or something like that.

I probably would not make it a Captain ability. It feels a little... too specific for that. You have to consider that almost everyone would use it then (assuming it didn't just suck), and that might get a little ridicilous.